# Copyright (c) 2014 Dark Secret Software Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import sys

from oslotest import base
import six

import monasca_common.simport.simport as simport


# Internal functions and classes.
def dummy_function():
    pass


class DummyClass(object):
    def method_a(self):
        pass


class LocalClass(object):
    def my_method(self):
        pass


PWD = os.path.dirname(os.path.abspath(__file__))


class TestSimport(base.BaseTestCase):

    def test_bad_targets(self):
        self.assertRaises(simport.BadDirectory, simport._get_module,
                          "|foo.Class")

        self.assertRaises(simport.MissingModule, simport._get_module,
                          "missing|")

        self.assertRaises(simport.MissingModule, simport._get_module,
                          "simport_tests|")
        self.assertRaises(simport.MissingModule, simport._get_module,
                          "simport_tests|Foo")
        self.assertRaises(simport.BadDirectory, simport._get_module,
                          "/does/not/exist|foo:Class")

        self.assertFalse("AnyModuleName" in sys.modules)
        self.assertRaises(simport.MissingMethodOrFunction, simport._get_module,
                          PWD + "|AnyModuleName:")
        self.assertFalse("AnyModuleName" in sys.modules)

    def test_good_external_targets(self):
        self.assertEqual(("localmodule", "Foo", "method_a"),
                         simport._get_module(PWD + "|localmodule:Foo.method_a"))

        self.assertRaises(simport.ImportFailed, simport._get_module,
                          PWD + "|that_module:function_a")

    def test_bad_load(self):
        self.assertRaises(simport.ImportFailed, simport.load,
                          "TestSimport:missing")

    def test_good_load_internal(self):
        self.assertEqual(six.get_function_code(dummy_function),
                         six.get_function_code(simport.load("test_simport:dummy_function")))
        self.assertEqual(six.get_function_code(DummyClass.method_a),
                         six.get_function_code(simport.load("test_simport:DummyClass.method_a")))

    def test_local_class(self):
        klass = simport.load("LocalClass", __name__)
        self.assertEqual(klass, LocalClass)

# Check python versions for importing modules.
# Python 2 import modules with full path to this module as a module name,
# for example:
# <module 'monasca_common.tests.external.externalmodule' from
# 'full_path/monasca-common/monasca_common/tests/external/externalmodule.py'>
#
# while Python 3:
# <module 'external.externalmodule' from 'full_path/monasca-common/monasca_common/tests/external/externalmodule.py'>
# , that's why we need to provide different module names for simport in Python 2 and 3
#

if six.PY2:

    class TestSimportPY2(base.BaseTestCase):

        def test_good_load_local(self):
            method = simport.load(PWD + "|monasca_common.tests.localmodule:Foo.method_a")
            import localmodule

            self.assertEqual(method, localmodule.Foo.method_a)
            self.assertEqual(localmodule.function_a,
                             simport.load("monasca_common.tests.localmodule:function_a"))

        def test_good_load_external(self):

            method = simport.load(PWD + "/external|monasca_common.tests.external.externalmodule:Blah.method_b")

            self.assertTrue('monasca_common.tests.external.externalmodule' in sys.modules)
            old = sys.modules['monasca_common.tests.external.externalmodule']
            import external.externalmodule

            self.assertEqual(external.externalmodule,
                             sys.modules['monasca_common.tests.external.externalmodule'])
            self.assertEqual(old, external.externalmodule)
            self.assertEqual(method, external.externalmodule.Blah.method_b)

        def test_import_class(self):
            klass = simport.load(PWD + "/external|monasca_common.tests.external.externalmodule:Blah")
            import external.externalmodule

            self.assertEqual(klass, external.externalmodule.Blah)

elif six.PY3:

    class TestSimportPY3(base.BaseTestCase):

        def test_good_load_local(self):
            method = simport.load(PWD + "|localmodule:Foo.method_a")
            import localmodule

            self.assertEqual(method, localmodule.Foo.method_a)
            self.assertEqual(localmodule.function_a,
                             simport.load("localmodule:function_a"))

        def test_good_load_external(self):

            method = simport.load(PWD + "/external|external.externalmodule:Blah.method_b")

            self.assertTrue('external.externalmodule' in sys.modules)
            old = sys.modules['external.externalmodule']
            import external.externalmodule

            self.assertEqual(external.externalmodule,
                             sys.modules['external.externalmodule'])
            self.assertEqual(old, external.externalmodule)
            self.assertEqual(method, external.externalmodule.Blah.method_b)

        def test_import_class(self):
            klass = simport.load(PWD + "/external|external.externalmodule:Blah")
            import external.externalmodule

            self.assertEqual(klass, external.externalmodule.Blah)